GEARED GAS TURBINE ENGINE AND A GEARBOX

• US 20180010525A1
• Filed: 06/21/2017
• Published: 01/11/2018
• Est. Priority Date: 07/08/2016
• Status: Active Grant

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: MADGE, Jason J.
• Granted Patent: US 10,364,753 B2
• Time in Patent Office: Days
• CPC Class Codes: B64D 35/00 Transmitting power from power plants to propellers or rotors; Arrangements of transmissions
• CPC Class Codes: F02C 7/32 Arrangement, mounting, or driving, of auxiliaries
• CPC Class Codes: F02C 7/36 Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user F02C3/107 - F02C3/13 and F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H
• CPC Class Codes: F05D 2260/40311 of the epicyclical, planetary or differential type
• CPC Class Codes: F05D 2260/53 using gears
• CPC Class Codes: F05D 2300/603 Composites; e.g. fibre-reinforced
• CPC Class Codes: F05D 2300/6032 Metal matrix composites [MMC]
• CPC Class Codes: F05D 2300/6033 Ceramic matrix composites [CMC]
• CPC Class Codes: F05D 2300/614 Fibres or filaments
• CPC Class Codes: F05D 2300/702 Reinforcement
• CPC Class Codes: F16H 1/02 without gears having orbital motion
• CPC Class Codes: F16H 57/082 Planet carriers
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A gas turbine engine comprises a gearbox comprising a sun gear, an annulus gear, a plurality of planet gears and a carrier. The carrier comprises a primary structure and at least one reinforcing structure. The primary structure comprises a first material and the at least one reinforcing structure comprises a second material. The primary structure includes a first ring, a second ring spaced axially from the first ring and a plurality of circumferentially spaced axles extending axially between the first ring and the second ring. Each planet gear is rotatably mounted on a respective one of the axles by a bearing. The reinforcing structure is secured to the primary structure and the reinforcing structure comprises a particulate reinforced material or a fibre reinforced material. The reinforcing structure increases the stiffness of the carrier and reduces the weight of the carrier.

Claims

1. A gas turbine engine comprising a gearbox, the gearbox comprising a sun gear, an annulus gear, a plurality of planet gears and a carrier, the sun gear meshing with the planet gears and the planet gears meshing with the annulus gear, the carrier comprising a primary structure and at least one reinforcing structure, the primary structure comprising a first material and the at least one reinforcing structure comprising a second material, the primary structure comprising a first ring, a second ring spaced axially from the first ring and a plurality of circumferentially spaced axles extending axially between the first ring and the second ring, each planet gear being rotatably mounted on a respective one of the axles, the at least one reinforcing structure being secured to the primary structure, and the at least one reinforcing structure comprising a reinforced material, the reinforced material being selected from the group consisting essentially of a particulate reinforced material and a fibre reinforced material.

2. A gas turbine engine as claimed in claim 1 wherein the at least one reinforcing structure is secured to the first ring.

3. A gas turbine engine as claimed in claim 1 wherein a first reinforcing structure is secured to the first ring and a second reinforcing structure is secured to the second ring.

4. A gas turbine engine as claimed in claim 1 wherein the first ring is selected from the group consisting essentially of an annular plate and an annular framework.

5. A gas turbine engine as claimed in claim 1 wherein the second ring is selected from the group consisting essentially of an annular plate and an annular framework.

6. A gas turbine engine as claimed in claim 1 wherein the primary structure comprises an unreinforced material.

7. A gas turbine engine as claimed in claim 6 wherein the primary structure comprises a metal selected from the group consisting essentially of steel, titanium, a titanium alloy, nickel, a nickel alloy, aluminium and an aluminium alloy.

8. A gas turbine engine as claimed in claim 1 wherein the reinforced material is selected from the group consisting essentially of a polymer matrix composite, a metal matrix composite and a ceramic matrix composite.

9. A gas turbine engine as claimed in claim 8 wherein the reinforced material is selected from the group consisting essentially of a polymer matrix composite with long reinforcing fibres, a metal matrix composite with long reinforcing fibres and a ceramic matrix composite with long reinforcing fibres.

10. A gas turbine engine as claimed in claim 9 wherein the first and second rings have a plurality of circumferentially spaced bosses, each axle locating in a corresponding one of the bosses in the first ring and a corresponding one of the bosses in the second ring.

11. A gas turbine engine as claimed in claim 10 wherein the long reinforcing fibres are arranged into at least one continuous loop arranged at a diameter greater than the diameter at which the bosses are arranged.

12. A gas turbine engine as claimed in claim 10 wherein the long reinforcing fibres are arranged in a star shape, the long reinforcing fibres in the star shape are wound partially around each boss of the first ring.

13. A gas turbine engine as claimed in claim 10 wherein the long reinforcing fibres are arranged in a star shape, the long reinforcing fibres in the star shape are wound fully around each boss of the first ring.

14. A gas turbine engine as claimed in claim 1 wherein the reinforced material is selected from the group consisting essentially of a polymer matrix composite with short reinforcing fibres, a metal matrix composite with short reinforcing fibres, a ceramic matrix composite with short reinforcing fibres, a polymer matrix composite with reinforcing particles, a metal matrix composite with reinforcing particles and a ceramic matrix composite with reinforcing particles.

15. A gas turbine engine as claimed in claim 1 wherein the primary structure comprises a particulate reinforced material.

16. A gas turbine engine as claimed in claim 15 wherein the particulate reinforced material of the primary structure is selected from the group consisting essentially of a polymer matrix composite, a metal matrix composite and a ceramic matrix composite.

17. A gas turbine engine as claimed in claim 16 wherein the reinforced material is selected from the group consisting essentially of a polymer matrix composite with long reinforcing fibres, a metal matrix composite with long reinforcing fibres, a ceramic matrix composite with long reinforcing fibres.

18. A gas turbine engine as claimed in claim 17 wherein the first and second rings have a plurality of circumferentially spaced bosses, each axle locating in a corresponding one of the bosses in the first ring and a corresponding one of the bosses in the second ring.

19. A gas turbine engine as claimed in claim 18 wherein the long reinforcing fibres are arranged into at least one continuous loop arranged at a diameter greater than the diameter at which the bosses are arranged.

20. A gas turbine engine as claimed in claim 18 wherein the long reinforcing fibres are arranged in a star shape, the long reinforcing fibres in the star shape are wound partially around each boss of the first ring.

21. A gas turbine engine as claimed in claim 18 wherein the long reinforcing fibres are arranged in a star shape, the long reinforcing fibres in the star shape are wound fully around each boss of the first ring or the second ring.

22. A gas turbine engine comprising a gearbox, the gearbox comprising a sun gear, an annulus gear, a plurality of planet gears and a carrier, the sun gear meshing with the planet gears and the planet gears meshing with the annulus gear, the carrier comprising a primary structure and at least one reinforcing structure, the primary structure comprising a first material and the at least one reinforcing structure comprising a second material, the primary structure comprising a first ring, a second ring spaced axially from the first ring and a plurality of circumferentially spaced axles extending axially between the first ring and the second ring, each planet gear being rotatably mounted on a respective one of the axles, the at least one reinforcing structure being secured to the primary structure, the primary structure comprises a particulate reinforced material and the at least one reinforcing structure comprising a fibre reinforced material.

23. A gearbox, the gearbox comprising a sun gear, an annulus gear, a plurality of planet gears and a carrier, the sun gear meshing with the planet gears and the planet gears meshing with the annulus gear, the carrier comprising a primary structure and at least one reinforcing structure, the primary structure comprising a first material and the at least one reinforcing structure comprising a second material, the primary structure comprising a first ring, a second ring spaced axially from the first ring and a plurality of circumferentially spaced axles extending axially between the first ring and the second ring, each planet gear being rotatably mounted on a respective one of the axles, the at least one reinforcing structure being secured to the primary structure, and the at least one reinforcing structure comprising a reinforced material, the reinforced material being selected from the group consisting essentially of a particulate reinforced material and a fibre reinforced material.